1. Field of the Invention PA1 2. Description of the Prior Art
This invention relates to piston engines and partially to double piston engines. Such double piston engines often operate as free piston engines. They may, however, also be provided with rotary means to control the timed relation of operation of the pistons in the cylinders.
A double piston engine is described in my U.S. patent application Ser. No. 06-529,254. In said application means are provided between the pistons to transfer the power of the combustion engine cylinders into reciprocating pistons of hydraulic pumps. Thereby the engine works as a hydrofluid combustion engine. Similar engines of hydrofluid conveying combustion engines are known from my U.S. Pat. Nos. 3,174,432; 3,260,213 and 3,269,321. A free piston engine is known from U.S. Pat. No. 4,385,597 to Frank Stelzer. The mentioned patents serve specific purposes and obtain them partially or totally. However, all of them are either still too heavy to permit the application in vertically taking off aircraft or they fail to have enough uniformity of flow if they are used to supply a flow or flows of hydraulic pressure fluid. Some of the mentioned engines also fail to have a uniform supply of power. In my mentioned earlier patents the forces of the combustion engine pistons are in equilibrium with the force consumption of the pistons of the hydraulic pumps. However, such equilibrium goes on the expense of uniformity of supply of power over time. The hydraulic hoses and pipes broke, thereby, under ununiform deliveries of fluid.